It’s sad that satsuki is going through those emotions but also very real, though thankfully he is a good person and realises how harmful his feelings are
Aw fuck I remember when my friends went through a situation like this both of them were dating and one of them came out as trans to us, his girlfriend started distancing himself from her because all she could do was think of him as a girl before he transitioned and that made her feel horrible but luckily they both worked it out it just upsets me so much so see another situation like that happening and I’m look forward to the conclusion!!
Satsuki just needs a break from his emotions. He could maybe get consultation from the uncle about how to get over crushes. Assuming satsuki is straight, he could double down on affirming rika's masculinity. Maybe get a hobby or something to occupy his mind.